The game was originally released for the Sega Mega Drive in North America and Europe on 23 June 1991, with a Japanese Mega Drive release following three days afterward on 26 June. Advertising its fast gameplay based on Sonic's extraordinary speed, the concept of a high-speed platform game was unique for its time and solidified the style of gameplay the series would be best known for. Due to the Mega Drive's Motorola 68000 processor, the power of the console would allow for faster gameplay, dubbed by some as "blast processing," and impressive 16-bit graphics, making it much more powerful than Sega's preceding Master System.

The game was well praised by critics and was a massive commercial success, which gave the Mega Drive, and by extent Sega, a huge boost in popularity, enough so that Sega could directly compete with Nintendo, who soon followed up with the release of their Super Nintendo Entertainment System. This would result in what would be the first counterattack in a long company rivalry that lasted throughout the 90s. In recent years, the game has been ported numerous times on many other consoles, with some ports adding newer features to the original game.

Contents

Plot

On the lush, tropical paradise of South Island, Sonic the Hedgehog's animal friends begin disappearing one by one. When he discovers that the evil scientist, Dr. Ivo Robotnik, has been kidnapping them and converting them into robotic Badniks as part of a plot to collect all six of the fabled Chaos Emeralds, Sonic decides it's up to him to save them, and embarks on a quest to free his friends and thwart the evil schemes of Robotnik.

As Sonic races through the Zones of the island, he engages in numerous confrontations with the nefarious Robotnik and his deadly machines, and one by one frees the animals from their robotic shells and capsules placed at the end of almost every zone. In their final confrontation, the Doctor prepares his last dastardly contraption to end his adversary but proves no match for Sonic's awesome might, and his machine is totaled. Fleeing with his tail between his legs, Robotnik abandons his laboratory as it explodes, crumbling to scrap, with Sonic narrowly escaping. Following his escape, Sonic finally returns to the vast Green Hills where his journey began.

In the game's normal ending, Sonic gives the player an annoyed look before posing for the screen, and Robotnik will be shown after the credits juggling all Chaos Emeralds the player missed, with a "Try Again" message taunting them.

However, if the player succeeds in collecting the six Emeralds by the end of the game, the player is rewarded with the good ending, where the six Chaos Emeralds react to one another and release a burst of light before disappearing, rejuvenating the wildlife and nature of South Island, leaving Sonic astonished before he jumps up towards the screen and poses. In the post-credits scene, Dr. Robotnik is shown humorously stomping on the "End" text in a tantrum-fueled attempt to crush it, to no avail.

Gameplay

Title screen of the game.

Sonic the Hedgehog plays identically to other platform games released around the same time, yet its primary focus is on fast gameplay and quick reflexes. The titular character can not only run and jump, but he can pick up incredible speed if uninterrupted and can roll into a ball and spin into enemies and up ramps with enough momentum, allowing him to launch himself high up into the air or through a stream of Badniks.

There are seven zones in total, with each zone, barring the Final Zone, divided into three Acts each. Sonic must reach the end of each Act within 10 minutes while collecting items and avoiding hazards along the way. Essential to the gameplay are gold Rings scattered throughout each level, a feature which would become one of the defining characteristics of the series. These items are regularly placed around the level map and serve multiple functions. First, the player collects rings to protect Sonic. As long as they have at least one ring, the player will not lose a life when injured. Instead, when hit, up to twenty of the rings the player has collected will fly outward and scatter around the immediate area for some seconds, some of which can then be retrieved before they disappear. If the player runs into an enemy without a single ring, he/she will lose a life. If the player collects a hundred rings they will gain an extra life, and will gain an additional life for every hundred rings after that, provided the rings are not lost.

If the player has at least fifty rings at the end of an act, a giant golden ring will float above the goal sign, which can be jumped through to enter one of the Special Stages (this excludes the final act of a stage, when Sonic will enter a boss fight). At the end of each act, the total number of rings the player has is multiplied by a hundred and added to the player's score. During the score-tallying, the player can also jump through the air to find hidden emblems which can range from a hundred to 10,000 points.

Also scattered throughout each level are video monitors which when broken by the character will reward the player with one of a variety of bonuses. These include a Shield which will protect Sonic from a single hit, a 10-ring bonus, an extra life, temporary Invincibility (accompanied by a temporary change in music), and "Power Sneakers", which give the player a temporary speed boost (and increase the tempo of the music for the duration). The item monitors have become another long-lasting feature in the series, though they have been changed to bubble-like containers that can float in later games.

Despite the various types of protection available, neither the shield, rings, nor invincibility will prevent the player losing a life if Sonic is crushed (by a trap or between a wall and a moving platform), drowned, runs out of time (each act has a ten-minute time limit), or falls into a bottomless pit.

Progression through the game is made easier for the player by lamp posts that act as checkpoints. When Sonic passes a lamp post, the spherical top spins around and its color changes from blue to red, and the next time a life is lost, gameplay will restart at that point rather than at the beginning of the act. In the Japanese version, if a checkpoint is activated and a life is lost as a result of running out of time, the time at the checkpoint will reset to 0:00.

Hazards the player experiences include a wide variety of "Badniks" - these appear as Animals trapped inside mechanical bodies which are released the moment the player hits them. Each badnik takes one hit to destroy, but they vary greatly from Zone to Zone; some will walk in a set path, others will try blasting the player, and some cannot be avoided at all. The player must also avoid rows of sharp spikes, cliffs, and elaborate death traps. There is also the threat of drowning (in Labyrinth Zone and the third Act of Scrap Brain Zone which contains water), as the player can only survive approximately thirty seconds underwater (locating air bubbles can extend this).

Sonic's abilities

Name

Sprite

Description

Walk

Push left or right on the D-pad to initiate Sonic's movement in either direction. As the player hold the button down, Sonic gains speed.

Run

Begin walking and hold down the button to make Sonic gain speed. After a few seconds, he'll break into a run.

Screech halt

While running, quickly press and hold the opposite direction on the D-pad to make Sonic screech to a halt. He'll skid for a short distance, based on how fast he was moving.

Look up

While standing still, press up on the D-pad to make Sonic gaze to the sky. As the player hold up, the camera pans upward, giving player a view of Sonic's overhead surroundings.

Crouch

While standing still, press down on the D-pad to make Sonic duck down. As the player hold down, the camera pans downward, giving player a view of the stage beneath where Sonic stands.

Often called the Spin Attack or just the roll in later games, pressing down on the D-pad while moving will make Sonic curl into a rolling attack. He'll remain in this position until the playe jump or slow down. The speed of Sonic's movement while in spin mode is based on how fast the player moving when player launch it, and also on the terrain Sonic rolls along.

Renamed the Spin Jump in later games, pressing an action button at any time will make Sonic leap into the air with a rolling attack. The height of the jump is proportional to how long the player hold the button down.

Push

Certain blocks can be pushed by running up against them. Continue holding the D-pad against the offending cube to have Sonic push it along the ground. This sprite will be shown if the player attempt this with an object that can't be pushed but won't harm player.

Zones

Sonic the Hedgehog has seven zones (plus the Special Stages). The first six zones contain three full-length Acts, and the final one only consists of the final boss machine.

Special Stages

If Sonic finishes the first or second Act of any of the first five zones with at least fifty Rings, a large, spinning ring will appear. If he jumps into it, he will warp into a "Special Stage" (called as the "Secret Zone" in the manual), which conceals one of the six Chaos Emeralds. In these stages, Sonic, in ball form, falls through a series of rotating mazes.

If he can avoid the "GOAL" signs along parts of the stage's walls (presumably labeled "GOAL" to entice the player into a failed attempt at getting a Chaos Emerald), he will eventually find the Chaos Emerald encased in colored diamonds; touching the diamonds repeatedly will cause them to change color from blue, to green, to yellow, to pink and ultimately disappear, allowing access to the Emerald. The stage will end when Sonic either touches the Emerald or hits a "GOAL" sign. If fifty Rings are collected before Sonic makes contact with a "GOAL" sign or gets the Chaos Emerald, then a 'Continue' will be awarded to the player, indicated by a brief, distinct change in melody. Super Sonic does not appear in Sonic the Hedgehog because the seventh Chaos Emerald was not yet introduced.

There are a total of ten opportunities to get Chaos Emeralds, meaning the player can fail a Special Stage up to four times if all six Emeralds are to be collected before the end of the game. Scrap Brain Zone will not have a large ring at the end of it, even when finishing with fifty rings, despite the acts ending before it. If the player fails a stage, that stage is skipped and is returned to after attempting the sixth and final Special Stage.

It is stated in the North American and European manuals that a 1-Up item can be found in Special Stages, but they are not seen anywhere unless placed in the game's secret Debug Mode. It is possible, however, to earn extra lives by collecting a hundred rings in a single stage, indicated by the same sound used in the main zones.

Items and power-ups

As long as Sonic has some of these, he won't lose a life if he takes damage. Sustain a hit, and all your collected Rings will scatter, giving you a brief opportunity to grab a few back before they disappear. (Rings will not protect Sonic from getting crushed by a trap, falling below the level, drowning, or running out of time. All of these effects result in instant death.) A 1-Up is awarded for every one hundred Rings collected, and each ring is worth a hundred points at the end-of-act score tally. In many later games, Sonic can collect fifty of these to transform into Super Sonic (if the player has all seven Chaos Emeralds).

Don't touch the pointy side! They're usually found in sets of three, but that's not a steadfast rule. Sometimes they're just lying out in the open, and sometimes they pop in and out of the ground, ceilings, or walls.

Large, oxygen-filled bubbles periodically rise from these clusters: tag one to fill Sonic's lungs with air and prolong the time you can spend underwater. Sonic can only spend thirty seconds underwater without drowning, and grabbing a bubble resets the timer. (Labyrinth Zone and Scrap Brain Zone Act 3 only)

These giant rings appear above bonus plates when you cross with at least fifty rings on hand. Jump in to warp to the Special Stage. (Once you've collected all six Chaos Emeralds, the Special Stage rings no longer appear.) If Sonic does not jump in before the bonus plate stops spinning, he will uncontrollably run off of the screen and the Special Stage is lost.

Blue bee bots that look like wasps with two yellow antennae with an engine that flies across from the right side of the screen, pausing once to fire a large flashing projectile from their stingers diagonally downward at Sonic. They are seen in Green Hill Zone.

These chameleon bots hang out on the side of cliffs and remain invisible until approached. They come in two colors: blue ones transform into missiles and jet along the ground. Green ones appear just long enough to fire an energy blast at Sonic.

Purple Caterpillar bots with yellow spikes on their body and two yellow antennae that crawl slowly along the ground. The safest method of disposal is to roll into their round heads: venture a poke anywhere else, and you'll sustain damage and send their segments flying. Caterkillers appear in Marble Zone and Scrap Brain Zone.

Blue bat bots with one engine, two black or gray claws, and black wings that latch onto ceilings until approached, then drop down and fly through the air a short distance before returning to their roost.

Blue armadillo bots with a red face that roll down long slopes after Sonic. They tumble faster than Sonic runs, so leap to avoid being steamrolled. At the bottom of the hill, Roller pauses and briefly opens up: this is your only chance to attack.

Mole bots with two tractor-like wheels, a blue head, and red shoulders, helmets, and arms that spring from underground and roll along the surface. Look for their drill bit noses poking out of the earth to avoid an ambush.

Irritable blue sphere bots that hover around very slowly. They're orbited by four red spiked balls which they fling off in rapid succession upon being approached. It's a dangerous assault, but once it's done, Unidasu is completely open to attack. ("Uni" is Japanese for sea urchin.)

These guys, palette aside, look exactly like Unidasu. They're a bit more cool-headed, though, with a green sphere in the middle and four yellow spikes surrounding it and won't fire off their barrier of orbs. While this means you don't have that tricky attack to avoid, they're virtually impossible to hit.

Mindless bots with gray top and red bottom with two gray legs. Even though they never move, they explode in five to six seconds after making contact with it into a shower of projectiles when approached. They can't be damaged, only avoided.

Blue rabbit robots that just bounce around. These badniks weren't used in the original release, but appeared in pre-release copies of the game and made appearances in promotional art. In the 2013 mobile re-release, they are enabled as solid objects in the game's Debug Mode.

Bosses

Dr. Robotnik

At the end of the third Act of each zone (except the Scrap Brain Zone), Sonic faces off against Dr. Robotnik, who is piloting his mobile. For each battle, Robotnik's machine has a different tactic. Sonic must hit each boss eight times to destroy it.

Master System and Game Gear

As the Master System still had high sales in South America (and in limited amounts in the US through retail stores), an 8-bit version of Sonic the Hedgehog was produced for the Master System market. This version had similar zone themes and regular enemies, but entirely different level layouts and bosses. The Master System version was released for the Wii Virtual Console on 4 August 2008. This version was also made available worldwide for the Game Gear, with adjustments due to the smaller screen.

Help Sonic fight hordes of metal maniacs and do theloop with the Super Sonic Spin Attack. Speed downtwisting tunnels and swing over dangerous booby traps.Leap across lava pits and dodge burning rocks. Thensplash through the chilling waters in an undergroundcavern. And if you’re lucky, you can warp to the secretzone where you spin around in a floating maze! Yourgreatest challenge lurks in a secret lab where you comeface to face with Dr. Robotnik himself!

Spin through space, loop ’til you’re dizzy, save theanimals and become the super hero. Be Sonic! Be atomic!

Gallery

Japanese

The evil mad scientist Dr. Eggman is up to his old nasty tricks again."Sonic…that annoying, impertinent hedgehog. Thanks to him, my great plans are always laid to waste! Oh, but this time, I'm going to rub him out with the power of science! Ha ha ha ha ha…"

South Island is a treasure trove of gems and ancient ruins. They say that it's the island where the mystical Chaos Emeralds lie. The Chaos Emeralds are a super-material that give energy to all living beings. Also, when applied to scientific purposes, they can be used for nuclear and laser based weaponry. However, nobody knows exactly how to get a hold of these emeralds. At the same time, though, they do say that the reason why South Island is always moving is because the emeralds are somewhere inside the island's hazy depths.

One day, crisis visited upon the island. And who showed up with it but Dr. Eggman and his cronies."I'll find those emeralds even if I have to dig up the entire island to do it!"

Dr. Eggman set up a fort in one corner of the island, and went about carrying out his plan.

"Eggman, you still haven't had enough?"Sonic hurried as soon as he heard the news. Dr. Eggman never seemed to leave him alone, even though Sonic had beaten him every time so far. It sounded like Dr. Eggman considered Sonic his sworn enemy, but he was never any match for Sonic.

However, this time something is amiss.

"Have you seen it, Sonic? This time is going to be different! Because this time, I've turned all the animals on the island into robots!"

"E...Everybody!?"

"All of them go about in accordance to my orders. In other words, Sonic, everyone on the island is your enemy! Gya— Ha ha ha ha ha ha ^cough^ ^ack^ ^ahem^. This time, the world really will be all mine!"

This is terrible! Hurry! Sonic the Hedgehog - everyone is waiting for your help!

Note: These codes do not work on the Xbox Live Arcade and PlayStation Network versions of the game. They also do not work in the game unlockable in the Xbox 360 version of Sonic Generations.

Glitches

There are six particular glitches in the game that could either help or make things much worse for Sonic.

Too fast Sonic in the Green Hill Zone; Result: If going too fast down two tubes in Green Hill, the camera won't respond and Sonic will die at the ledge to the giant ring pattern.

Rolling after Labyrinth Zone Act 2's end; Result: An illegal instruction error will proceed if this glitch is triggered, making the player reset the game.

Too many hits on the Final Zone's boss; Result: If timed correctly, the player can hit Robotnik two times on the final hit, showing that he would need to be hit 255 more times, which is normally impossible under the time limit.

Sonic jumps too far away in the Final Zone; Result: Sonic would jump off into the bottomless pit, therefore losing a life.

Move through walls in Scrap Brain Zone; Result: On one of the moving platforms, Sonic can duck and go through the wall, showing that he has been placed in another location.

"Spike Bug"; Result: Though this is technically intentional, Sonic isn't invulnerable to spike damage immediately after taking a hit. This causes instant death (or an endless loop, if on debug mode). This was fixed in later games and in certain ports.

Re-releases

Included in Sonic Compilation (later released as Sonic Classics) on the Sega Mega Drive.

Sega Mega Drive

Re-released on the Sega Mega Drive in a new package under a "Sega Classics" logo.

Sega Mega Drive

Mega 6 Volume 3 was a Sega Mega Drive cartridge consisting of six games, one of which was Sonic the Hedgehog.

Sega Mega Drive

6-Pak was a Sega Mega Drive cartridge consisting of six games, one of which was Sonic the Hedgehog.

Arcade

This was one of the games adapted for release in arcades using MegaPlay and MegaTech technology in 1993. The game is almost identical to the console version except Labyrinth Zone and Scrap Brain Zone Act 3 have been removed.

Sonic Gems Collection allows you to play the final boss of this game in the museum mode. If you beat the Final Zone under the time limit, you can continue on to the beginning of the game until your time runs out.

In 2005 this game was ported as a mobile phone game and offered on the Sonic Cafe service in Japan.

Mobile Phone

Sonic the Hedgehog Mobile is an emulated version of the game released for download on Mobile phones in 2005, under the Sega Mobile banner. However, the game is split into two parts. Part 1 contains the first 3 zones, while Part 2 contains the last three.

Play TV Legends

Sega Mega Drive Collection Vol. 1 is a game console which is part of the Play TV Legends plug-and-play series. It has 6 built-in games that can be played when the console is connected to the TV. The title game is Sonic the Hedgehog. This was released in Europe and the US in 2005.

Play TV Legends

Included in Super Sonic Gold, a console that has 4 built in games, but no cartridge slot. Released in the US and Europe in 2005

Released on the Game Boy Advance under the title Sonic the Hedgehog Genesis. While it added Spin Dash and save features, the port is considered of extremely poor quality due to incompetent programming.

iPod

Sonic the Hedgehog (iPod); iTunes recently released this "Click Wheel Game" version for download under the Sega Mobile banner. It was compatible with the iPod Nano (3rd, 4th, 5th Generation) and iPod classic (5th Generation). Not to be confused with the iOS port.

iOS

Sonic the Hedgehog was ported to iOS in May 2009. This version's distribution has been discontinued, replaced by an entirely different port with the Retro Engine (see below).

Available for Download on the PlayStation 3's PlayStation Network service. Available to PlayStation Plus Members (for Free) from 1 March 2011 to 5 April 2011. Available to Regular Users 29 March 2011.

Android (Kyocera Echo only)

Available for Download on Kyocera Echo via G-Gee by Gmo. It was available for free (including other games by G-Gee and SEGA's Super Monkey Ball) for a short period of time.

Xbox 360 / PlayStation 3

In the console versions of Sonic Generations, this game is playable from the hub world. It is unlockable after a Genesis controller is purchased from the Skill Shop. This version keeps track of time (similar to the release of Sonic Jam). In addition, a new bonus feature can be unlocked via the Skill Shop - infinite continues. The Xbox 360 version lacks the level select code, but the PlayStation 3 version has it intact. It is removed from the PC version in favor of slightly enriching the core game experience.

As a celebration of the Mega Drive's 25th anniversary in Japan, Sega released another port for Nintendo 3DS titled 3D Sonic the Hedgehog, which is part of series of Mega Drive games re-released to take advantage of 3D. The port also features Spin Dash as optional move, Stage Select feature, input settings, sound settings, the option to toggle the original revisions, and separate display settings with stereoscopic sense to create a 3D experience. It is was released in Japan on 15 May 2013,[5] and was later released in North America and PAL Regions on December 5, 2013.[6][7]

Nintendo 3DS

Sonic the Hedgehog is one of the Sega games included in a compilation of classic games titled Sega 3D Classics Collection. While it is titled 3D Sonic the Hedgehog, this compilation title takes advantage of stereoscopic 3D to create a 3D experience.

Rereleased as part of the SEGA AGES line for the Nintendo Switch, Sonic the Hedgehog includes some features such as the Spin Dash and Drop Dash from Sonic Mania and two modes: Ring Keep Mode and Time Attack. It was released on September 20, 2018.

Reception

The original Sonic the Hedgehog was very well received by critics, scoring 86% from GameRankings.[8] The game was an instant success that allowed Sega to wrap their video game business around and have a platformer to compete with Nintendo's Super Mario franchise.[9] The gameplay, audio and graphics were praised by reviewers.

IGN reviewer Lucas M. Thomas rated Sonic the Hedgehog an 8/10, praising the simple but fast gameplay, the soundtrack and commended that "few people realize how difficult it was to create Sonic's graphics engine, which allowed for the incredible rate of speed the game's known for. The technical achievement impressed back in '91, and still does so today."[10] Gamespot reviewer Greg Kasavin gave the game a 7.3/10, praising the great soundtrack and memorable sound effects, the fast-paced, responsive platformer action and cute, colorful graphics [that] have a good deal of charm and personality although he felt that the later levels can get frustrating tough, requiring meticulous memorization.[11]

Trivia

The Japanese release added additional storyline details, as the existing plot was virtually a basic outline. The purpose of the Chaos Emeralds is greatly expanded upon, which is elaborated in later games. It is explained that Dr. Robotnik was specifically searching for them on the island due to their incredible energy according to legend. The manual also states that there has already been some unknown animosity between Sonic and Robotnik in the past (which, on the other hand, is not backed up in later games). It also lists the setting as South Island, which is established in later games as well - in the English manual, the setting was originally unnamed.

There are two versions of the game. This revision is common in Japan, but contrary to popular belief it was released worldwide in smaller quantities. This update makes some very minor changes to the game's programming, as well as adds some visual effects such as scrolling clouds in Green Hill Zone or water ripples in Labyrinth Zone. It also corrects the Zone order on the level select. This version of the game is used in most subsequent releases. In addition, the scrolling clouds return in most appearances of Green Hill Zone.

Rui Sousa holds the high score for Sonic the Hedgehog: 1,559,180. He achieved this on 21 March 2015.[12]

There was a sound test that was originally supposed to be in this game but was scrapped. But one character in this sound test appeared in future games (Vector) while the others appear in the Archie Comics as part of Mina Mongoose's band.